Ultrasound diagnostic devices are used for the inspection of various parts in the body such as the abdomen and the heart. The ultrasound diagnostic devices, having advantages like harmlessness to living tissues in contrast to X-ray inspection, simple and easy operation, and possibility of video observation in real time, are widely used today. In the ultrasound diagnostic device, an ultrasound probe emits an ultrasonic wave toward the test object and receives a reflected wave from a tissue inside the test object. Based on the received reflected wave, an ultrasound image of the tissue (test object) is displayed on a monitor. In the capturing of ultrasound images, it is possible to acquire two-dimensional images or three-dimensional images in real time by scanning a converged ultrasonic wave (ultrasound beam converged in a particular direction) with respect to the azimuth direction.
Since doctors have to find and diagnose minute lesions (tumors, etc.) by observing ultrasound images by use of ultrasound diagnostic devices, the ability to acquire ultrasound images with high visibility is required of the ultrasound diagnostic devices. Further, the definition of display monitors is improving fast especially in these years, and thus enhancement of the resolution of ultrasound images is being requested accordingly.
To meet the above request, it is possible to acquire a high-resolution ultrasound image by increasing the resolution with respect to the scan azimuth direction by increasing the number of scans of the ultrasound probe per frame. It is also possible to generate a high-resolution image by conducting a deconvolution process to an acquired image for one frame (one frame image) as described in Patent Literature 1. A technique described in Non-patent Literature 1 is known as an example of the deconvolution process, in which an ideal ultrasound image with no deterioration is estimated from an acquired ultrasound image through the modeling of image blurring caused by the aberration of the ultrasound beam and image deterioration caused by the sampling.
In a method described in Patent Literature 2, the body motion of the object under consideration (considered object) in the imaging plane is measured by using ultrasound images. Information varying with time (the shape of the considered object, tissue degradation, etc.) is visualized and displayed by adding up or subtracting time-line images while compensating for the measured body motion.